An Oakland, California, startup called AnimalBiome analyzes the levels of bacteria in the guts of cats and dogs to see if they’re out of whack. The company then offers the pets’ owners a “poop pill,” encapsulated fecal samples from animals with healthy guts, to rebalance the so-called microbiome. In healthy pets, as in humans, hundreds of types of bacteria—some good, some bad—perform an intricate dance that strikes a balance that generally keeps animals healthy by snaring and digesting nutrients from food. When one or a handful of bacteria start to dominate the digestive tract, the result is conditions such as chronic diarrhea or vomiting. AnimalBiome’s goal is to stop inflammation caused by those conditions that can lead to life-shortening diseases, such as cancer. The cost: Up to $300 for a package of tests and oral "gut-restoration supplements.” That’s a lot of money for something pets usually eat for free—only not in pill form.